Method and apparatus for measuring of masks for the photo-lithography

US8730474B2 · kind B2 · utility

Assignee

• Carl Zeiss SMS Ltd. · IL

Inventors

• Thomas Scheruebl · Jena, DE
• Holger Seitz · Jena, DE
• Ulrich Matejka · Jena, DE
• Axel Zibold · Jena, DE
• Rigo Richter · Zeulenroda, DE

Key dates

• Filing date: Mar 19, 2009
• Grant date: May 20, 2014
• Expiry date: Sep 26, 2030

Classification

• Technology area (CPC G): Physics
• CPC primary: G03F7/70775
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

The invention relates to a method and an apparatus for measuring masks for photolithography. In this case, structures to be measured on the mask on a movable mask carrier are illuminated and imaged as an aerial image onto a detector, the illumination being set in a manner corresponding to the illumination in a photolithography scanner during a wafer exposure. A selection of positions at which the structures to be measured are situated on the mask is predetermined, and the positions on the mask in the selection are successively brought to the focus of an imaging optical system, where they are illuminated and in each case imaged as a magnified aerial image onto a detector, and the aerial images are subsequently stored. The structure properties of the structures are then analyzed by means of predetermined evaluation algorithms. The accuracy of the setting of the positions and of the determination of structure properties is increased in this case.